JP2000343231A - Motor incorporated type driving unit for motor-driven welding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor incorporated type driving unit for a motor-driven welding machine, where a motor shaft and a screwed shaft are integrated in the motor resulting in a formation of a short driving unit with a reduced moment of inertia, a compact and handy unit, is improved in flexibility of using by a free choice of the combination of the motor shaft and the screw shaft, and further realizes an easy assemblying and an excellent maintainability. SOLUTION: In the motor-driven welding machine equipped with a movable arm or a swing arm driven by a motor 1, a bore 7 is drilled at the driving end of a motor shaft 5, and one end of a screwed shaft 8 is inserted and fixed into the bore, a screw 10 is provided at the other end of the screwed shaft, and a nut 15 formed on a pressurizing shaft 11 is engaged with the screw.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive unit for an electric welding machine provided with a movable arm or a swing arm driven by a motor.

[0002]

2. Description of the Related Art Conventionally, as a drive unit of an X-type welding machine having a swinging arm driven by a motor, for example, as disclosed in Japanese Utility Model Registration No. 3042268,
A ball screw shaft is provided on an output shaft derived from a motor via a transmission, and a ball screwed to one end of the ball screw shaft is provided.
It is known that a threaded screw is engaged with a ball nut formed on a pressure shaft (hereinafter referred to as the former).

[0003] Also, a movable arm driven by a motor is provided.
As a drive unit of a C-type welding machine provided with a system, for example, as disclosed in Japanese Patent Application Laid-Open No. Hei 7-290251, a motor shaft is hollow, and a ball screw shaft is passed through the hollow portion. It is also known that a ball screw formed on a screw shaft is engaged with a ball nut fixed to the motor shaft (hereinafter referred to as the latter).

[0004]

However, in the former case of the above-mentioned conventional example, an output shaft derived from the motor is a drive unit for swinging the swing arm by driving the motor. Since the ball screw shaft is provided via the transmission device, the entire length of the drive unit becomes longer, and there is a possibility that the operation becomes unstable when the electric welding machine is operated.

[0005] In the latter case of the above-mentioned conventional example, the length of the drive unit is shortened, but the ball nut is fixed to the motor shaft inside the motor, so that the motor is not driven. As the diameter increases and the outer diameter of the ball nut is larger than that of the ball screw, the moment of inertia increases and the acceleration / deceleration time increases when the electrode opens and closes during motor operation. In addition, a special motor that has an effect on the heat capacity of the motor and accommodates a large-diameter ball nut is required. Therefore, welding spatter and cooling water may be directly applied to the screw thread.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to integrate a motor shaft and a screw shaft in a motor. The drive unit is shortened and the inertia moment is reduced, making it compact and easy to use.The combination of the motor shaft and screw shaft can be freely selected, improving flexibility, and further improving assembly and maintainability. It is an object to provide a motor-integrated drive unit in a good electric welding machine.

[0007]

In order to achieve the above-mentioned object, a motor-integrated drive unit in an electric welding machine according to the present invention is provided with a hole formed in an output side of a motor shaft, and the hole is formed in the hole. One end of the screw shaft is inserted and fixed, a screw is screwed on the other end of the screw shaft, and a nut formed on the pressure shaft is engaged with the screw.

[0008] The present invention is further characterized in that a mounting portion for a handle for manual operation is formed at the other end of the motor shaft.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. In the drawing, reference numeral 1 denotes a servomotor, which is composed of a stator winding 3 fixed to an outer shell 2, a rotor magnetic pole 4 arranged on the inner periphery thereof, and a rotor magnetic pole. 4 comprises a fixed motor shaft 5 which is supported by bearings 6 and 6 on the outer shell 2 of the motor 1. The output side of the motor shaft 5 is provided with a hole 7 into which a ball screw shaft described later is inserted.

Reference numeral 8 denotes a ball screw shaft. One end of the ball screw shaft 8 is inserted into the hole 7.
A power lock mechanism 9 utilizing a wedge action of an inner ring and an outer ring is disposed between the ball screw shaft 8 and the motor shaft 5. The shaft 8 is fixed to the motor shaft 5. Therefore, the ball screw shaft 8 is supported by the common bearing 6 with the motor shaft 5. A ball screw 10 is screwed on the other end side of the ball screw shaft 8 outside the motor 1.

Reference numeral 11 denotes a movable arm by a trunnion shaft 12.
And a pressure shaft connected to a swing arm (not shown). The pressure shaft 11 is rotatably supported by a bearing 14 in the housing 13 so as to be non-rotatable and reciprocable. A ball nut 15 meshing with the ball screw 10 is integrally provided at the rear end of the pressure shaft 11 (not shown). Reference numeral 16 denotes an encoder fitted on the outer periphery of the motor shaft 5.

In the above-described drive unit, when, for example, a three-phase current is supplied to the stator winding 3 of the servomotor 1 in the state shown in the drawing, the rotor magnetic poles 4 are excited and the motor shaft 5 rotates. Then, the ball screw shaft 8 integrated with the motor shaft 5 rotates. A ball nut 15 which meshes with the ball screw 10 of the ball screw shaft 8 with the rotation of the ball screw shaft 8
The movable arm or the oscillating arm performs a pressurizing operation via the trunnion shaft 12 due to the forward movement of the pressurizing shaft 11.

Thus, the ball screw shaft 8 is connected to the motor shaft 5
Since the bearing of the ball screw shaft 8 is shared with the bearing of the motor shaft 5, the length of the ball screw shaft 8 is longer than that of the conventional drive unit. The length of the welding gun is shortened and the length thereof is reduced. Further, the inertia moment received by the motor 1 is also reduced, so that the movement response of the welding electrode by the motor 1 is remarkably improved, and the motor shaft 5 and the ball screw shaft 8 are further improved.
Is a different product, so that the combination can be freely selected, the flexibility is improved, the assembly and maintenance are improved, and the drive unit is effective for obtaining a compact and easy-to-use electric welding machine.

Since the ball screw shaft 8 and the motor shaft 5 are locked by a tightening means utilizing a wedge action, the ball screw shaft 8 is released by releasing the lock.
Can be easily extracted from the table 1. Further, the mode
In the case where the mounting portion 17 of the handle for manual operation is formed at the other end of the motor shaft 5, when the motor 1 breaks down,
The movable arm or the swinging arm can be guided to a desired open position by manually rotating the motor shaft 5 and the ball screw shaft 8 by attaching a handle (not shown) to the arm.

[0015]

According to the drive unit of the present invention, a hole is formed on the output side of the motor shaft, one end of the screw shaft is inserted into the hole and fixed, and a screw is mounted on the other end of the screw shaft. And the nut formed on the pressurizing shaft is meshed with the screw, so that the length is shortened as compared with the conventional drive unit. become,
Further, since the inertia moment received by the motor is also reduced, the responsiveness of movement of the welding electrode by the motor is significantly improved, and the drive unit is effective for obtaining a compact and easy-to-use electric welding machine. .

If a handle for manual operation is formed at the other end of the motor shaft, when the motor fails, the handle is mounted on the mount and the motor shaft and the motor are manually operated. Since the movable arm or the swing arm can be guided to a desired open position by rotating the screw shaft, the drive unit can respond immediately to a motor failure.

[Brief description of the drawings]

FIG. 1 is a sectional view of a motor-integrated drive unit in an electric welding gun according to the present invention.

[Explanation of symbols]

 1 Motor 5 Motor shaft 7 Hole 8 Screw shaft 9 Power lock mechanism (Fixing device) 10 Screw 11 Pressure shaft 15 Nut 17 Handle mounting part

Claims (2)

[Claims] An electric welding machine provided with a movable arm or a swinging arm driven by a motor, wherein a hole is formed in an output side of a motor shaft, and the screw shaft is provided in the hole. A motor integrated type in an electric welding machine, wherein one end is inserted and fixed, a screw is screwed on the other end of the screw shaft, and a nut formed on the pressure shaft is engaged with the screw. Drive unit. 2. A motor-integrated drive unit in an electric welding machine according to claim 1, wherein a mounting portion for a handle for manual operation is formed at the other end of said motor shaft.